The conventional DCC Command Centre is a dedicated computational device, and costs several hundred pounds to buy, Hornby have substituted an Application running on an ubiquitous Android device (phone or tablet). The App is free from Hornby, then you need a power supply for the track, "tinkerers" (I have a strong background in electronics) will probably buy a supply to power the track from Ebay, (eg a Meanwell supply) for £12 to £20.
Think of that, the entry point of DCC , the Command Centre, is not £200 to £400, but is down to £10 to £20, for the cost of a power supply from Ebay.